    package filter;
    import bean.User;
    import javax.servlet.*;
    import javax.servlet.annotation.WebFilter;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import javax.servlet.http.HttpSession;
    import java.io.IOException;

    @WebFilter(filterName = "loginFilter",urlPatterns = {"/*"})
    public class loginFilter implements Filter {
        @Override
        public void destroy() {
        }
        public void init(FilterConfig config) throws ServletException {

        }

        @Override
        public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) resp;
        User user = (User) request.getSession().getAttribute("user");

            if(request.getRequestURI().contains("index.jsp")||request.getRequestURI().contains("/login/dgut")||user!=null)
                chain.doFilter(req,resp);
            else
               response.sendRedirect("https://cas.dgut.edu.cn?appid=javaee");

        }

    }
